组件源码

using UnityEngine;using System.Collections;//This script allows to drag rigidbody2D elements on the scene with orthographic camera//Attach this script to your camerapublic class DragRigidbody2D : MonoBehaviour{    public float Damper = 5f;    public float Frequency = 3;    public float Drag = 10f;    public float AngularDrag = 5f;        private SpringJoint2D _springJoint;    private Camera _camera;    private RaycastHit2D _rayHit;        void Start ()        {        _camera = gameObject.GetComponent
    
     ();        }                void Update ()     {        if (!Input.GetMouseButtonDown(0))            return;        //Looking for any collider2D under mouse position        _rayHit = Physics2D.Raycast(Camera.main.ScreenToWorldPoint(Input.mousePosition), Vector2.zero);        if (_rayHit.collider == null)            return;                if (!_rayHit.collider.rigidbody2D || _rayHit.collider.rigidbody2D.isKinematic)            return;        if (!_springJoint)        {            //Create spring joint            GameObject go = new GameObject("[Rigidbody2D_dragger]");            Rigidbody2D body = go.AddComponent
     
      ();            _springJoint = go.AddComponent
      
       ();            body.isKinematic = true;        }            _springJoint.transform.position = _rayHit.point;            _springJoint.anchor = Vector2.zero;        //Apply parameters to spring joint            _springJoint.frequency = Frequency;            _springJoint.dampingRatio = Damper;            _springJoint.distance = 0;            _springJoint.connectedBody = _rayHit.collider.rigidbody2D;            StartCoroutine("DragObject");        }    IEnumerator DragObject()    {        var oldDrag = _springJoint.connectedBody.drag;        var oldAngDrag = _springJoint.connectedBody.angularDrag;        _springJoint.connectedBody.drag = Drag;        _springJoint.connectedBody.angularDrag = AngularDrag;        while (Input.GetMouseButton(0))        {            Vector2 newPos = _camera.ScreenToWorldPoint(Input.mousePosition);            _springJoint.transform.position = new Vector2(newPos.x, newPos.y);            yield return new WaitForSeconds(0.1f);        }        if (_springJoint.connectedBody)        {            _springJoint.connectedBody.drag = oldDrag;            _springJoint.connectedBody.angularDrag = oldAngDrag;            _springJoint.connectedBody = null;        }    }}
      
     
    

使用方法

Drag预览